Field of the Invention
The present invention relates to an electronic component and a manufacturing method thereof and, more particularly, to a coil component such as a common mode filter and a manufacturing method thereof.
Description of Related Art
A common mode filter, which is known as one of electronic components, is widely used as a noise suppression component for a differential transmission line. Recent progress of manufacturing technology allows the common mode filter to be realized as a very small surface mount chip component, and a coil pattern to be incorporated is significantly reduced in size and space.
Further, in a common mode filter of so-called a thin film type, there is known a common mode filter in which an external terminal electrode is increased in thickness by plating (see, e.g., Japanese Patent application Laid-open No. 2011-14747). In a common mode filter of this type, when the external terminal electrode and a planar coil pattern are connected to each other, an internal terminal electrode connected to an inner or outer peripheral end of the planar coil pattern is connected to the external terminal electrode. An insulating layer is interposed between the external and internal terminal electrodes, and the external terminal electrode is connected, in a planar fashion, to a top surface of the internal terminal electrode through an opening formed in the insulating layer.
With recent miniaturization of a chip size, an area of the internal terminal electrode has significantly been reduced. When the external terminal electrode is connected to the internal terminal electrode having such a small area, a joint strength between the internal and external terminal electrodes may be insufficient, so that an electrical connection failure can easily be caused due to thermal shock and so on. Such a problem occurs notably in the above-mentioned common mode filter; however, it occurs not only for terminal electrode connection in the common mode filter but also for terminal electrode connection in various electronic components, and a solution to this problem is desired.